A number of multiple filament lamp sockets and other superficially related lamp sockets have heretofore been proposed. Those of which the applicant are aware are disclosed in Dulberg U.S. Pat. Nos. 2,222,655 issued 26 November 1942 for "MULTIPLE FILAMENT LAMP COMBINATION"; Schultz 1,666,248, issued 17 April 1928 for "THREE-WAY LAMP SOCKET"; and Truitt 625,219 issued 16 May 1899 for "ELECTRIC SWITCH"; and also, LEVITON has a switch and socket device on the market.
Each of the foregoing references discloses switching devices that are incapable of pull-chain control of a multiple filament electric lamp. The Schultz and LEVITON switch and socket mechanisms are designed only to control single filament electric lamps.
As shown in FIGS. 18 and 19, the LEVITON device has four arcuate surfaces in a circle on a non-conductive support member 200. Contacts 202 and 204 are formed on two arcuate surfaces in opposing quadrants. Contact 202 is connected to an electric power source, and contact 204 is connected to the filament 208 of a single filament electric lamp. A conductive bar 210 rotates from an "OFF" position shown in FIG. 18, in which it rests on the non-conductive support member 200, to an "ON" position, shown in FIG. 10, in which it rests on contacts 202 and 204. In the "ON" position, current may flow from power source 206, through conductive bar 210, and through filament 208. Filament 208 is thus energized, and the light bulb becomes luminous. Conductive bar 210 is rotated using a standard pull-chain type rotation actuator. The LEVITON device would energize only one filament of a standard multiple filament electric lamp.
On the other hand, Truitt and Dulberg, while allowing control of a multi-filament lamp, do not provide for control of such lamps using a pull-chain actuating device.